It will be convenient to hereinafter describe the invention with particular reference to an example power tool of the electrically operated hand-held type, but it needs to be understood that the invention has wider application. An example tool of the foregoing type is an angle grinder. Again, as a matter of convenience, the invention will be hereinafter described with particular reference to such a grinder.
Power tools of the foregoing kind tend to develop high temperatures at the work face, and that has the disadvantage of reducing the useful working life of the operative element (e.g., cutting tool, grinding wheel, etc.). In some cases, and particularly relatively large machine tools such as lathes, the temperature problem is attended to by means of a stream of a liquid coolant directed at the work face. That method of cooling is not suited for all types of power tools, and is particularly not suited for use with portable hand-held power tools.